Drive assembly



A. c. WRIGHT 3,014,519

DRIVE ASSEMBLY Filed May 25, 1959 Dec. 26, 1961 INVENTOR.

ALLEN c. WRIGHT mfg/214e@ 9L 75M 3,014,5l9 Y BREVE ASSEMBLY Allen C. Wright, Lafayette, Calif., assigner to L & B Welding Equipment, line., a corporation of California Filed May 25, 1959, Ser. No. 815,558 8 Claims. (Cl. 153-100) My invention relates to drive assemblies and more particularly to drive assemblies adapted to produce relative movement between a housing and a wire or rod running axially of said housing. The invention is particularly applicable to the feeding of wire to the work in lauto-V matic and semi-automatic welding and will be described with respect to such application.

In automatic or semi-automatic welding, electrode wire is fed from a reel to the work. In accordance with conventional practice, the wire is threaded between a pair of drive rollers which function to push such wire through a length of ilexible casing terminating in a tip through which the wire emerges to be consumed by the welding arc in forming a weld.

To accomplish such drive with rollers, one or both of such rollers is customarily knurled and this invariably roughens up the surfaceV of the Wire, which not only increases the drive force necessary to push the wire through the tiexible casing, but also results in rapid wearing of the tip through which the Wire emerges from the tlexible casing. Also, the wire coming 01T the reel is necessarily curved which further increases the drive force necessary to maintain smooth and continuous movement of the wire through such casing.

Among the objects of the present invention are:

(l) To provide a novel and improved drive assembly;

(2) To provide a novel and improved `drive assembly adapted to produce relative movement between a housing and a wire or rod running through said housing;

(3) To provide a novel and improved drive assembly for feeding wire from a reel;

(4) To provide a novel and improved drive assembly for electrode Wire in automatic and semi-automatic welding, which not only will not mar or roughen the surface of such wire, but will actually tend to smooth out surface roughness existing on the wire as it comes off the reel;

(5) To provide a novel and improved drive assembly for electrode wire in automatic and semi-automatic welding, which will function to straighten out any curves or l bends in the wire fed therethrough;

(6) To provide a novel and improved drive assembly for electrode Wire in automatic and semi-automatic welding, which may be utilized to roll a bevel on an end of the wire to facilitate initial threading thereof through the drive assembly and the llexible casing;

(7) To provide a novel and improved drive assembly for electrode wire in automatic and semi-automatic welding, which will automatically accommodate itself to electrode wire of various diameters within a substantial range of sizes.

Additional objects of my invention will be brought out in the following description of a preferred embodiment of the same, taken in conjunction with the accompanying drawings wherein:

FIG. l is a View in section. through a'drive assembly of the present invention in its preferred form and as adapted for the feeding of electrode wirein a Welding system; v

FIG. 2 is a view in section taken in the plane 2-2 of FIG. l;

FIG. 3 is a view in section taken in the plane 3-3 of FIG. l; and

' FIG. 4 is a schematic showing of the Wire feed porf 3,@ l 4,5 i 9 Patented Bec. 26, l 961 'i ce tion of such a welding system, with the invention located therein.

Referring to the drawings for details of my invention in its preferred form as applied to welding, the drive assembly l depicted therein comprises a pair of roller group assemblies 3 and 5, each including a substantially cylindrical housing 7 having a plurality of side openings 9 through which to insert and assemble, a plurality of elongated cylindrical rollers i3, each roller preferably having each end thereof terminating in a cylindrical section l5 of reduced diameter. These rollers, which preferably are three in number, are grouped within the housing 7 about the longitudinal axis thereof and with the rollers at an angle to each other.

To so group and mount these rollers, I provide a pair of anchor blocks 2l, 23 within the housing and in spaced relationship to each other, one of the blocks 21 being of insulation material such as canvas base Micarta, and lixed Within an end of the housing while the other block 23 which may be of aluminum or other metal, is rotatably positioned within the other end and spaced from the xed block 2l by a snap ring 25 sprung into a groove in the housing Wall.

Each of the anchor blocks has a wire passage opening 27 therethrough and a plurality of self-aligning bearing assemblies 29, equal in number to the number of rollers and symmetrically distributed about such wire passage opening. A self-aligning bearing assembly is one involving an outer race and an inner race, the inner race being capable of a partial swing of the order of 8 degrees in all directions from the central axis of the assembly.

To obtain the desired angular position of the rollers, each such bearing assembly is installed in its anchor block with its central axis at an angle of the order of l0 degrees with the axis of the housing 7. This is accomplished by recessing or drilling the anchor blocks at such an yangle and counterboring the same to receive the bearing assembly.

With the bearing assemblies so installed, the rollers may then be assembled by rotating the block 23 to bring its bearing assemblies into alignment with the bearing assemblies in the fixed block, and this will leave the rollers grouped about the axisV of the housing in their desired angular relationship with respect to each other. The employment of selfaligning bearing assemblies provides a measure of adjustment of the angularity of the rollers whereby the space within the group of rollers may be restricted orl enlarged within limits to pass Wire 33 of different sizes within a limited range. i

I prefer to spring load the group of rollers to normally urge them to their most space restrictive position however, whereby wires of different diameter within the permissible range of acceptance by the device, when threaded into engagement with the rollers, will spread the Vrollers against the action of the spring loading and thus assure the rollers maintaining'a good drive grip on the wire. 4

Such spring loading means includes a closure cap 35 of insulation material such as canvas base Micarta, for the housing adjacent the rotatable anchor blockl 23, said cap being recessed to form a spring chamber 37, and being further provided with a Wire passage 39 in line with that of the anchor blocks. A plurality of springs 41,' each having one end connected to a point represented by a peg i2 on the rotatable anchor block 23 and its other end connected to the closure cap 35at a point represented by a peg 43 angularly displaced from the first point in a direction to minimize such space within the roller group, are tensioned by rotating the closure cap slightly beyond the point Where the rollers contact each other, following which the closure cap is lixed to the housing as by set screws 45 or other means. Such springs preferably equal in number the number of rollers.

Both roller group assemblies, for drive purposes, are supported in spaced alignment Within a casing 51, on a plurality of ball bearing assemblies 53, both the fixed anchor block 21 and xed closure cap 35 of each roller group assembly, extending beyond the ends of their housing to provide for such mounting, with the fixed anchor blocks 21 facing each other. Suitable spacer sleeves 55, 57 are disposed within the casing to properly maintain the roller group assemblies properly located within the casing.

To drive the roller group assemblies, a bushing 59, preferably fixed at one end in one of the iixed anchor blocks and supported at its other end in a suitable recess provided in the opposing fixed anchor block, carries a pair of opposing bevel gears 61, 63, each secured to the adjacent fixed anchor block 2i.

A motor 67 attached to the casing and carrying a bevel pinion 69 in mesh with the opposing bevel gears, will simultaneously rotate both roller group assemblies, but in opposite directions. To correct for such opposite direetion of rotation, one of the roller assemblies is constructed in reverse to the other, whereby both roller group assemblies will act in the same direction upon a wire `or rod passing through the drive assembly.

When driven by the motor, the rollers, in moving around the -wire in engagement therewith, will be caused to rotate on their own axis to produce a reactive force between the rollers and the wire. With the rollers maintained against linear movement, the reactive force will necessarily result in linear movement of the wire through the drive assembly. The direction of movement of the of rotation of the motor will determine the direction wire, thus enabling the drive assembly to function in either direction merely through control of the direction of rotation of the motor.

Guide sleeves 75 may be provided through each rotatable anchor block 23 and similarly, a guide sleeve 77 may be provided through the fixed anchor blocks 2.1, and bushing 59.. When provided, they will terminate in a tapered edge before reaching the midsection of the rollers to leave the wire exposed for drive engagement with the rollers.

For guiding welding wire into the drive assembly, a closure cap 81 of insulation material, such as canvas base Micarta, at one end of the casing 51, is provided with a counterbo-red wire passage S3 therethrough, to

eceive one end of a guide tube S5 which may be fixed thereto by a set screw 37.

At the other end of the casing, a closure cap 91 also of insulation material such as canvas base Micarta, is

provided with an enlarged counterbored wire passage 93 to receive one end of a iiexible casing 9S which is likewise fixed in position by a suitable set screw 97.

Making the anchor blocks 21 and closure caps 35, 81 and 91 of insulation material, serves to electrically insulate the electrode Wire 33 from the casing S1 which in all likelihood will be electrically grounded along with the motor casing aiiixed thereto.

By mounting the drive assembly in a fixed position in the line of travel of electrode wire 33 from a reel 101 to the work to be welded, electrode wire fed into one end of the drive assembly will be pulled from the reel lill and pushed through the flexible casing 95 to the work, the rolling action of the rollers not only not marring the surface of the wire, but in fact tending to smooth out any prevailing roughness of the wire as it comes oic the reel.

The drive assembly also functions as a straightening die and will serve to remove any bends or kinks in the wire as the wire is driven through.

In severing wire, whether it be ordinary wire or the electrode Wire used in welding, the end is usually distorted out of round and may terminate in a sharp and rough edge. This ordinarily would pose a problem in threading such wire into any equipment into which the wire has to be fed. The present drive assembly offers a solution to such problem. I have found that by temporarily reversing the direction of rotation of the rollers so as to reject or oppose the movement of wire through the assembly, and then manually feeding the end of such Wire into the drive assembly, the proximate group of rollers will roll a taper or bevel on the end of the wire. The drive assembly can then be restored to its conventional direction of rotation and the wire will then feed through with no difficulty.

While the drive assembly in its preferred form, incorporates a pair of roller group assemblies, a single roller group assembly will, of itself, constitute a drive assembly, and with the ability to straighten the wire and roll a bevel in the end thereof. However, a single roller group assembly, inherently `tends to rotate the wire pass ing through, and this tendency is neutralized by employing a pair of roller group assemblies in the manner indicated as the preferred form of the invention. In addition, the utilization of a pair of roller group assemblies incre-ases the power of the drive assembly.

While the invention was described from the viewpoint of its application to welding, where the drive assembly is maintained iixed and the wire travels, it becomes apparent that if the wire were held stationary and the drive assembly were free to move, it would travel along the wire, thereby enabling the basic drive assembly of the present invention to be adapted for use for a variety of purposes.

Accordingly, I do not desire to be limited in my protection to the specific details illustrated and described except as may be necessitated by the appended claims.

Iclaim:

l. A drive assembly for producing relative movement between a housing and a rod or wire running through said housing, said drive assembly comprising a roller group assembly including a housing, a plurality of elongated substantially cylindrical rollers, means grouping said rollers within said housing about the path of travel of such wire therethrough and with said rollers at an angle to each other, said means including a pair of anchor blocks, one fixed and one rotatable within said housing and in spaced relationship to each other, each of said anchor blocks having a wire passage opening and a plurality of self-aligning bearing assemblies equal in number to the number of rollers and symmetrically distributed about said wire passage opening with each bearing assembly installed with its central axis at an angle of the order of ten degrees to said path of travel and outside of any plane through said path of travel, one of said anchor blocks being oriented with respect to the other such that the central axis of each bearing assembly thereof is in substantial alignment with the central axis of a bearing assembly of the other anchor block, said rollers each being installed with its ends in such aligned bearing assemblies, means for spring loading said group of rollers to normally reduce to a minimum the space bounded by said rollers, said spring loading means including a closure cap for said housing and fixed thereto adjacent said rotatable anchor block, and at least one spring having one end connected to a point on said rotatable block and its other end connected to said iixed closure cap at a point angularly displaced from said first point in a direction to minimize such space; a second roller group assembly similar to said first roller group assembly except in that the rollers of said second roller group assembly are angularly reversed to those of said first roller group assembly; and means for rotatably driving both said roller group assemblies on a common axis, said means including a casing, bearing means supporting said roller group assemblies in alignment within said casing, with their fixed anchor blocks facing each other in spaced relationship, a bevel gear afxed to each of said iixed anchor blocks, and a drive motor mounted on said casing and having a drive pinion in mesh with said bevel gears.

2. A drive assembly for producing relative movement between a housing and a rod or wire running axially of said housing, said drive assembly comprising a roller group assembly including a housing having side openings, a plurality of elongated substantially cylindrical rollers, means grouping said rollers within said housing about the longitudinal axis thereof and with said rollers at an angle to each other, said means including a pair of anchor blocks, one fixed and one rotatable within said housing and in spaced relationship to each other, each of said anchor blocks having a wire passage opening and a plurality of self-aligning bearing assemblies equal in number to the number of rollers and symmetrically distributed about said wire passage opening with each bearing assembly installed with its central axis at an angle of the order of ten degrees to the housing axis and outside of any plane through said housing axis, one of said anchor blocks being oriented with respect to the other such that the central axis of each bearing assembly thereof is in substantial alignment with the central axis of a bearing assembly of the other anchor block, said rollers each being installed with its ends in such aligned bearing assemblies, means for spring loading said group of rollers to nor? mally reduce to a minimum the space bounded by saidl rollers, said spring loading means including a closure cap for said housing and fixed thereto adjacent saidV rotatable anchor block, and at least one spring having one end connected to a point on said rotatable block and its other end connected to said lixed closure cap at a point angularly displaced from said iirst point in a direction to minimize such space; a second roller group assembly similar to said first roller group assembly except in that the rollers of said second roller group assembly are angularly reversed to those of said rst roller group assembly; and means for rotatably driving both said roller group assemblies on a common axis, said means including a casing, bearing means supporting said roller group assemblies in alignment within said casing with their fixed anchor blocks facing each other in spaced relationship, a bevel gear affixed to each of said fixed anchor blocks, and a drive motor mounted on said casing and having a drive pinion in mesh with said bevel gears.

3. A drive assembly for producing relative movement between a substantially, cylindrical housing and a rod or wire running axially of said housing, said drive assembly comprising a roller group assembly including a substantially cylindrical housing having side openings, a plurality of elongated substantially cylindrical rollers, each rollerhaving each end thereof terminating in a cylindrical section of reduced diameter, means grouping said rollers within said housing about the longitudinal axis thereof and with said rollers at an angle to each other, said means including a pair of anchor blocks, one iixed and one rotatable within said housing and in spaced relationship to each other, each of said anchor blocks having a wire passage opening and a plurality of self-aligning bearing assemblies equal in number to the number of rollers and symmetrically distributed about said wire passage opening with each bearing assembly installed with its central axis at an angle of the order of ten degrees to the housing axis and outside of any plane through said housing axis, one of said anchor blocks being oriented with respect to the other such that the central axis of each bearing assembly thereof is in substantial alignment with the central axis of a bearing assembly of the other anchor block, said rollers each being installed with its ends in such aligned bearing assemblies, means for spring loading said group of rollers to normally reduce to a minimum the space bounded by said rollers, said spring loading means including a closure cap for said housing and iixed thereto adjacent said rotatable anchor bloclt, and at least one spring having one end connected to a point on said rotatable block and its other end connected to said xed closure cap at a point angularly displaced from said first point in a direction to minimize such space; a second roller group assembly similar to said first roller group assembly except in that the rollers of said second roller group assembly are angularly reversed to those of said iirst roller group assembly; means for rotatably driving both said roller group assemblies on a common axis, said means including a casing, bearing means supporting said roller group assemblies in alignment within said casing, with their iixed anchor blocks facing each other in spaced relationship, a bevel gear aliixed to each of said ixed anchor blocks, and a drive motorfmounted on said casing and having a drive pinion in mesh with said bevel gear; and a closure for each end of said casing having a wire passage therethrough.

4. A drive assembly for producing relative movement between a housing and a rod or Wire running through said housing, said drive assembly comprising a roller group assembly including a housing, a plurality of substantially cylindrical rollers, and means grouping said rollers within said housing about the path of travel of such wire therethrough and with said rollers at an angle to each other, said means including a pair of anchor blocks, one fixed and one rotatable within said housing and in spaced relationship to each other, each of said anchor blocks having a wire passage opening and a plurality of bearing openings equal in number to the number of rollers and symmetrically distributed about said wire' .passage opening with the central axis of each such bearing opening at an angle to said path of travel and outside of any plane through said path of travel, said rotatable anchor block being oriented with respect to the other such that the central axis of each such bearing opening is in substantial alignment with the central axis of a bearing opening of the other anchor block, and said rollers each being installed with its ends in such aligned bearing openings; means for spring loading said rotatable anchor block about its axis to yieldably reduce to a minimum,

the space bounded by said rollers; and means for rotatably driving said roller group assembly about its longitudinal axis.

5. A drive assembly for producing relative movement between a housing and a rod or wire running through said housing, said drive assembly comprising a roller group assembly including a housing, a plurality of substantially cylindrical rollers, means grouping said rollers .within said .housing about the path of travel of such wire therethrough and with said rollers at an angle to each other, said means including a pair of anchor blocks, one iixed and one rotatable within said housing` and in spaced relationship to each other, each of said anchor blocks having a wire passage opening and a plurality of bearing assemblies equal in number to the number of rollers and symmetrically distributed about said wire passage opening with each bearing assembly installed with its central axis at an angle to said path of travel and outside of any plane through said path of travel, said rotatable anchor block being oriented with respect to the other such that the central axis of each bearing assembly thereof is in substantial alignment with the central axis of a bearing assembly of the other anchor block, said rollers each being installed with its ends in such aligned bearing assemblies, and means for spring loading said rotatable anchor block about its axis to yieldably reduce to a minimum the space bounded by said rollers; and means for rotatably driving said roller group assembly about its longitudinal axis.

6. A drive assembly for producing relative movement between a housing and a rod or wire running through said housing, said drive assembly comprising a roller group assembly including a housing, a plurality of elongated substantially cylindrical rollers, means grouping said rollers within said housing about the path of travel of such wire therethrough and with said rollers at an angle to each other, said means including a pair of anchor blocks, one lixed and one rotatable within said housing and in spaced relationship to each other, each of said anchor blocks having a wire passage opening and a plurality of bearing assemblies equal in number to the number of rollers and symmetrically distributed about said wire passage opening with each bearing assembly installed with its central axis at an angle of the order of ten degrees to said path of travel and outside of any plane through said path of travel, one of said anchor blocks being oriented with respect to the other such that the central axis of each bearing assembly thereof is in substantial alignment with the central axis of a bearing assembly of the other anchor block, said rollers each being installed with its ends in such aligned bearing assemblies, means for spring loading said group of rollers to normally reduce to a minimum the space bounded by said rollers, said spring loading means including a closure cap for said housing and xed thereto adjacent said rotatable anchor block, and at least one spring having one end connected to a point on said rotatable block and its other end connected to said fixed closure cap at a point angularly displaced from said rst point in a direction to minimize such space; and means for rotatably driving said roller group assembly about its longitudinal axis.

7. A drive assembly for producing relative movement between a housing and a rod or wire running through said housing, said drive assembly comprising a roller group assembly including a housing, a plurality of elongated substantially cylindrical rollers, means grouping said rollers within said housing about the path of travel of such wire therethrough, and with said rollers at an angle to each other, said means including a pair of anchor blocks, one xed and one rotatable within said housing and in spaced relationship to each other, each of said anchor blocks having a wire passage opening and a plurality of self-aligning bearing assemblies equal in number to the number of rollers and symmetrically distributed about said wire passage opening with each bearing assembly installed with its central axis at an angle of thev order of ten degrees to said path of travel and outside of any plane through said path of travel, one of said anchor blocks being oriented with respect to the other such that the central axis of each bearing assembly thereof is in substantial alignment with the central axis of a bearing assembly of the other anchor block, said rollers each being installed with its ends in such aligned bearing assemblies, means for spring loading said group of rollers to normally reduce to a minimum the space bounded by said rollers, said spring loading means including a closure cap for said housing and ixed thereto adjacent said rotatable anchor block, and at least one spring having one end connected to a point on said rotatable block and its other end connected to said fixed closure cap at a point angularly displaced from said rst point in a direction to minimize such space; and means for rotatably driving said roller group assembly about its longitudinal axis, said means including a casing, bearing means supporting said roller group assembly within said casing, a bevel gear affixed to said fixed anchor block, and a drive motor mounted on said casing and having a drive pinion in mesh with said bevel gear.

8. A drive assembly for producing relative movement between a substantially, cylindrical housing and a rod or wire running axially of said housing, said drive assembly comprising a roller group assembly including a substantially cylindrical housing having side openings, a plurality of elongated substantially cylindrical rollers, means grouping said rollers within said housing about the longitudinal axis thereof and with said rollers at an angle to each other, said means including a pair of anchor blocks, one fixed and one rotatable within saidhousing and in spaced relationship to each other, each of said anchor blocks having a wire passage opening and a plurality of self-aligning bearing assemblies equal in number to the number of rollers and symmetrically distributed about said wire passage opening with each bearing assembly installed with its central axis at an angle of the order of ten degrees to the housing axis and outside of any plane through said housing axis, one of said anchor blocks being oriented with respect to the other such that the central axis of each bearing assembly thereof is in substantial alignment with the central axis of a bearing assembly of the other anchor block, said rollers each being installed with its ends in such aligned bearing assemblies, means for spring loading said group of rollers to normally reduce to a minimum the space bounded by said rollers, said spring loading means including a closure cap for said housing and xed thereto adjacent said rotatable anchor block, and at least one spring having one end connected to a point on said rotatable block and its other end connected to said xed closure cap at a point angularly displaced from said iirst point in a direction to minimize such space; and means for rotatably driving said roller group assembly about its longitudinal axis, said means including a casing, bearing means supporting said roller group assembly within said casing, a bevel gear aixed to said fixed anchor block, a drive motor mounted on said casing and having a drive pinion in mesh with said bevel gear; and a closure for each end of said casing having a wire passage therethrough.

References Cited in the ille of this patent UNITED STATES PATENTS 320,531 Beauregard et al June 23, 1885 760,406 Gregersen May 17, 1904 1,190,698 Abramson July l1, 1916 1,909,019 Seward May 16, 1933 2,067,972 Leech Jan. 19, 1937 2,779,384 Knauth et al Jan. 29, 1957 

